Toxic Coma

1. Toxic Coma Presented By Dr/ Said SaidElshama

2. Introduction Conscious state is awareness and arousal. Awareness • Receive and process all the information communicated by the five senses. • It consists of psychological and physiological components. • The psychological component is controlled by the mind and mentality . • The physiological component is function of brain (physical and chemical ). • Awareness is regulated by cortical areas within the cerebral hemispheres, Arousal • It is regulated by physiological function . • It consists of involuntary responses to stimuli. • It is maintained by the reticular activating system (RAS). Reticular activating system (RAS) • It is not an anatomical area of the brain. • It is a network of structures (brainstem and thalamus) and nerve pathways, which function together to produce and maintain arousal.

3. Definition Coma - It is a state of profound loss of conscious .  - It is characterized by :- • No spontaneous eye openings (Loss of voluntary movement) • No response to painful stimuli and speech. • No arousal (Loss of normal reflexes) • It is a result of any agent that interferes with the function of cerebral cortex or function of RAS (brainstem and thalamus)

4. Causes &Types 1- Anatomic al (structural ) - Damage of brain structures (cerebral cortex ,brainstem) - Lateralizing signs = unequal pupil size , asymmetry of tone and deep reflexes Ex. (trauma “head injury”, space-occupying lesion “tumor, hematoma, cerebral edema” Vascular disease” thrombosis, hemorrhage, embolism” 2-Toxic - Metabolic encephalopathy - Change of chemical of brain and function. Ex. Hypoxia “co, cyanide “ hypo-hyper glycaemia, electrolyte abnormalities “hypo-hyper natremia” , metabolic acidosis (uncontrolled diabetes), endocrine (hypothyroidism), hypo – hyper thermia ”heat stroke” Ex . Toxins and drugs overdose • Toxins (internal & external) affect on the function of neurons. • External = Drugs or alcohol • Internal = ammonia, urea

5. 3- Infection with encephalitis ( septic coma) 4- Seizures - electrical disturbance leads to changes in chemical levels of brain 5- Alpha coma - Dominant alpha-wave activity in EEG 6-Irreversible coma Brain death- irreversible arrest of all brain function 7- Coma vigil Locked in syndrome a rare neurological condition. awake and alert, with a normal mind with total paralysis except for eye muscles. 8- Persistent vegetative state Intact functions of the brain stem and circulation 9- Anoxic brain injury. It result from  (cardiac arrest), head injury or trauma, drowning, drug overdose, or poisoning.

6. Common Toxic Agents • Opiate • Barbiturates • Benzodiazepines • Neuromuscular blockers • Tricyclic antidepressants • Hallucinogens • Anti cholinergic drugs • Alcohol • Co - Cyanide • Organophosphorous

7. Management of Comatose Patient 1- Life - saving measures: A- Airway B- Breathing C- Circulation 2-Assessment - Level of conscious ( Glasgow coma scale). - Diagnosis (history , neurological exam, investigations). - Intervention according to the cause.

8. Glasgow Coma Scale • It measures depth of coma . • Eye opening • Vocal response • Motor response • Ratings range from 3 -15. 1- Total rating of 3 -5 indicates very severe brain injury 2-Total rating of 6 - 8 indicates severe brain injury (still in coma) 3- Total rating of 9 - 15 indicates brain injury out of coma Total rating of 9 - 12 indicates moderate TBI Total rating of 13 - 15 indicates mild TBI

9. Glasgow Coma Scale Eye OpeningVerbal Response Spontaneous 4 Oriented 5 To loud voice 3 Confused, Disoriented 4 To pain 2 Inappropriate words 3 None 1  Incomprehensible words 2 None 1  Motor Response Obeys commands 6 Localizes pain 5 Withdraws from pain 4 Abnormal flexion posturing 3 Extensor posturing 2 None 1 • A fully awake patient has a Glasgow  Coma Score of 15. • A dead person who has a Glasgow  Coma Scale of 3 (there is no lower score).

11. Barbiturates Poisoning • It is a sedative – hypnotic drugs • Classification according to duration of action. • Duration of action depends on:- • Rate of metabolism • Rate of excretion • Distribution properties (lipid soluble , protein binding, ionization) • More lipid soluble, more binding , non ionization= more distribution • Long acting (6-12 hr) • Phenobarbitone – blood and urine • Intermediate acting (4-6 hr) • Amy barbital- urine • Short acting (3 hr) • Secobarbital- urine • Ultra short acting (15-30 M) • Thiopental – urine

12. Acute Barbiturate Poisoning Significant toxicity =4 mg/dl(long acting) ,2 mg/dl(short) Acute barbiturate poisoning may be cause acute brain death because of a prolonged hypoxia . Clinical picture :- • Deep prolonged coma • Loss of reflexes ( deep tendon reflex ) • Dilated pupil • Slow respiration or rapid shallow(cheyne stoke), Cyanosis • Hypotension-Weak rapid pulse • Hypothermia • Nephritis (hamaturia, albuminuria) • Skin rash

13. Chronic Barbiturate Poisoning • Amnesia • Tremor • Ataxia - Cerebellar affection “incoordination, slurring speech” • Rash • Renal affection (haematuria, albuminuria)

14. Management of Barbiturate Poisoning 1- Life saving measures 2- Symptomatic treatment 3- Assessment 4- Investigations (Phenobarbitone plasma level, Renal function tests, E.C.G , Arterial blood gases) 4- Git decontamination (lavage , charcoal) 5- Elimination • Forced alkaline diuresis • Peritoneal dialysis • Haemodialysis • Haemoperfusion

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